The plural form is challenges.
there isnt a plural form of a.
"Daffodils" is the plural of "daffodil."
The plural form is digits; the singular form is digit.
The plural form of three is threes.
"Argumental" is not considered to be a genuine word in the dictionary, so technically it has no part of speech.
Yes, "argument" is a singular noun. The plural form is "arguments".
common form of moral arguments
There is no plural form. Do and Do not are verbs
Bridges is the plural form of bridge.
The plural form of him, her, or it is them. (objective pronouns)
The plural form of "is" is "are."
The plural form of "was" is "were."
The plural form of mouth is mouths. The plural form of month is months. The Mounth is a range of hills in Scotland and does not have a plural form.
"Groceries" is the plural form of "grocery."
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
The plural form of the demonstrative pronoun 'that' is those.